1. Field of the Invention
The present invention is a ball valve cartridge especially adapted for use in applications where it is actuated by a remotely positioned handle, such as in freezeless wall hydrants or faucets and yard hydrants.
2. Description of the Prior Art
The field of valves for regulating and controlling fluid flow is certainly well developed. Self-draining yard hydrants and freezeless wall faucets, wall hydrants, sillcocks or bibcocks, are also well known.
Yard hydrants are described in many US Patents, including U.S. Pat. No. 4,372,339. Freezeless wall hydrants are also described by many U.S. Patents, including my prior U.S. Pat. No. 5,158,105.
A freezeless sillcock with ceramic disk valve elements is described in U.S. Pat. No. 6,880,573. This device has an operating range constituting only one quarter of a turn of an actuator handle. However, the components of the ceramic disk are contained within a cartridge and, in a commercial embodiment of this invention, the disks are under heavy compression exerted by very strong springs. That makes this unit subject to failure due to spring failure, as well as failure of the disks themselves. Ceramic has a very different co-efficient of expansion than steel and brass and copper and, in extreme temperatures such as those encountered in the freezeless application under consideration, this may lead to failure, as well. Ceramic disk cartridges can retain water so that freezing may lead to catastrophic failure. The flow rate through ceramic disk valve elements is generally less than the flow rate through a comparable ball valve element. Flow rate is also limited in ceramic valve elements by size limitations imposed by the ceramic material itself. Ceramic disk valve elements are more prone to sediment blockage than ball valve elements. Ceramic valve elements are made of ceramics while ball valve elements can be made of almost any material including, without limitation, brass, stainless steel, iron, PVC, Delrin, nylon and so on.
Generally speaking, the machining of ceramic parts can leave flaws which can cause premature failure of those parts. Ceramic parts generally cost more than do metal parts. Because ceramics are so hard, mating surfaces tend to wear more quickly than mating surfaces of parts made from other materials. The hardness of ceramics makes them generally more difficult to machine. Ceramics require more expensive abrasive materials and must be machined more slowly than metal to avoid damage.
It is submitted that there is a need for a cartridge style valve that is actuated over a quarter turn, like the ceramic freezeless ceramic disk valve hydrant mentioned above, that is more reliable, easier to produce, less expensive, and more resistant to extreme temperature fluctuations such as those encountered in freezeless hydrant applications.